Nuprl Lemma : total-function-rational-approx

∀f:ℝ ⟶ ℝ. ∀y:ℝ.  ((∀x,y:ℝ.  ((x = y) ⇒ (f[x] = f[y]))) ⇒ lim n→∞.f[(y within 1/n + 1)] = f[y])


Proof




Definitions occuring in Statement :  converges-to: lim n→∞.x[n] = y,  rational-approx: (x within 1/n),  req: x = y,  real: ℝ,  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  add: n + m,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  implies: P ⇒ Q,  so_lambda: λ2x.t[x],  uall: ∀[x:A]. B[x],  real: ℝ,  nat_plus: ℕ+,  nat: ℕ,  le: A ≤ B,  and: P ∧ Q,  decidable: Dec(P),  or: P ∨ Q,  iff: P ⇐⇒ Q,  not: ¬A,  rev_implies: P ⇐ Q,  false: False,  prop: ℙ,  uiff: uiff(P;Q),  uimplies: b supposing a,  subtract: n - m,  subtype_rel: A ⊆r B,  top: Top,  less_than': less_than'(a;b),  true: True,  so_apply: x[s]
Lemmas referenced :  total-function-limit,  rational-approx_wf,  decidable__lt,  false_wf,  not-lt-2,  condition-implies-le,  minus-add,  minus-one-mul,  zero-add,  minus-one-mul-top,  add-commutes,  add_functionality_wrt_le,  add-associates,  add-zero,  le-add-cancel,  less_than_wf,  nat_wf,  rational-approx-converges-to,  all_wf,  real_wf,  req_wf
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  hypothesis,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  sqequalRule,  lambdaEquality,  isectElimination,  setElimination,  rename,  because_Cache,  dependent_set_memberEquality,  addEquality,  natural_numberEquality,  productElimination,  unionElimination,  independent_pairFormation,  voidElimination,  independent_functionElimination,  independent_isectElimination,  applyEquality,  isect_memberEquality,  voidEquality,  intEquality,  minusEquality,  functionEquality,  functionExtensionality

Latex:
\mforall{}f:\mBbbR{}  {}\mrightarrow{}  \mBbbR{}.  \mforall{}y:\mBbbR{}.    ((\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (f[x]  =  f[y])))  {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.f[(y  within  1/n  +  1)]  =  f[y])



Date html generated: 2017_10_03-AM-10_21_53
Last ObjectModification: 2017_06_30-PM-04_15_10

Theory : reals


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